There is known a device for taking samples from a fermenter comprising a sampler and a by-pass valve, this device being widely known in laboratory research practice.
The use of such a device for sample taking necessitates the employment of an open flame to treat conduits wherethrough a liquid being tested is passed from the fermenter to the sampler, the nipple of the sampler being necessarily immersed into an antiseptic solution. The sampler normally has a cotton plug which is removed in the flame zone during sample taking and set into place after terminating the sample taking procedure. The by-pass valve is provided with a clamp handled by one more attendant. The device described heretofore is difficult to operate, while the range of its possible application is rather limited, since it is impossible to take samples of explosive or inflammable fluids.
There is also known a device for taking samples from a fermenter comprising a by-pass valve mountable at the outlet of the fermenter, and a sampler having its own by-pass valve arranged at the inlet thereof.
The by-pass valve of the sampler has a spring-loaded rod, an annular groove and a sealing element, whereas the by-pass valve of the fermenter is provided with a spring-loaded rod and an annular projection defining during cooperation with the annular groove of the sampler valve a hermetically sealed separating chamber for the passage of a sample fluid therethrough (cf., e.g., USSR Inventor's Certificate No. 726,833, published 1979).
Prior to taking a sample from the fermenter, it is necessary that the sampler be sterilized and an underpressure or vacuum be induced therein, whereupon the sampler must be hermetically coupled with the by-pass valve of the fermenter, and by depressing the sampler the latter is filled with a culture suspension to be examined.
However, inherent in the device of the above construction is a disadvantage in that it fails to maintain sterility of the mating surfaces of the by-pass valves of the sampler and fermenter, whereby the fluid to be tested is susceptible to contamination after this fluid passes the separating chamber, the fluid may also be contaminated both in the fermenter and in the sampler.